A workpiece stress distribution inversion system and method based on longitudinal and transverse wave fusion and a storage medium

Abstract

The application discloses a workpiece stress distribution inversion system and method based on longitudinal and transverse wave fusion and a storage medium, and relates to the technical field of residual stress measurement. The system comprises an ultrasonic detection module, a workbench and a control module. The method comprises the following steps: acquiring the acoustic time of longitudinal and transverse waves when the workpiece to be measured is in zero stress, and calculating the corresponding acoustic-elastic coefficient; transmitting ultrasonic waves to the workpiece to be measured to calculate the propagation distance, calculate the propagation speed of the ultrasonic longitudinal and transverse waves when the workpiece to be measured is in zero stress, and further calculate the actual propagation time of the longitudinal and transverse waves of each grid in the detection area; based on the travel-time residual inversion algorithm, the actual propagation speed of the longitudinal and transverse waves of all grid areas in the cross section of the workpiece to be measured is calculated, the longitudinal and transverse wave velocity tomographic images of the cross section are generated, the residual stress of each position of the cross section of the workpiece to be measured is calculated by fusion, and the residual stress tomographic images of each position of the cross section of the workpiece to be measured are generated. The application has high measurement precision, and the workpiece to be measured does not need to be moved for multiple times for detection of the same cross section.

Description

Technical Field

[0001] This invention relates to the field of residual stress measurement technology, and more specifically, to a workpiece stress distribution inversion system, method, and storage medium based on longitudinal and transverse wave fusion. Background Technology

[0002] During the manufacturing process, workpieces are affected by various technological and material factors. If these factors cannot be completely eliminated, residual stress will form. The presence of residual stress will cause changes in the size and shape of the object: when residual stress exists within a deformed object, the object will undergo corresponding elastic deformation or lattice distortion; if the residual stress disappears, the corresponding deformation will also disappear, causing changes in the size and shape of the object. The presence of residual stress will shorten the lifespan of parts, posing a significant hazard to equipment such as aircraft and rockets where dimensional tolerances for components are extremely high. The rationality of the distribution and the appropriateness of the magnitude of residual stress in a workpiece are important indicators for its use. Measuring residual stress helps to understand the distribution of residual stress in the workpiece, predict material service safety, improve workpiece manufacturing processes, and increase the service life and safety of the workpiece.

[0003] Currently, residual stress measurement mainly includes non-destructive testing (NDT) and destructive testing (DDT). DDT uses stress release methods, such as blind hole testing and chemical testing, but these methods can cause irreversible damage to the workpiece. During the measurement process, cutting or other actions can damage and cause yielding of the workpiece, affecting the measurement results. Non-destructive methods include X-ray methods, neutron diffraction, and ultrasonic methods. X-ray methods, due to the limited penetration depth of X-rays, can only measure residual stress on the material surface. If measuring residual stress inside the material or measuring stress gradients, the X-ray measurement capability is significantly reduced, failing to meet requirements. Neutron diffraction is limited by the required equipment and cannot be performed on-site, restricting its commercial application. Ultrasonic methods, with their advantages of high testing speed, large measurement depth, low hardware cost, simple operation, harmlessness to humans, and non-destructive testing, have attracted widespread attention from academia and industry and are a promising method in NDT.

[0004] Current ultrasonic testing methods for residual stress at different depths in workpieces measure it by exciting critically refracted longitudinal waves using ultrasonic waves of different frequencies incident at an angle. This method can only measure residual stress on the workpiece surface and at relatively shallow depths, and cannot measure all depths within the coverage area. It requires continuous movement of the device for measurement, which is not only time-consuming and labor-intensive, but also prone to inaccurate results due to changes in environmental conditions, failing to provide strong supporting data for experimental results. Furthermore, since residual stresses are interactive, measurements of residual stress in a small area cannot yield more comprehensive and complete analytical results. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, which cannot measure all depths of the coverage area and requires continuous device movement, this invention provides a workpiece stress distribution inversion system, method, and storage medium based on longitudinal and transverse wave fusion.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] Firstly, a workpiece stress distribution inversion system based on longitudinal and transverse wave fusion includes an ultrasonic detection module and a worktable, wherein the ultrasonic detection module is connected to the worktable and is communicatively connected to a control module.

[0008] The ultrasonic detection module includes a longitudinal wave probe group and a transverse wave probe group, which are used to transmit and receive longitudinal waves and transverse waves respectively, and return the received longitudinal wave and transverse wave signal data to the control module.

[0009] The control module is used to control the ultrasonic detection module to emit and receive longitudinal and transverse waves, receive longitudinal and transverse wave signal data returned by the ultrasonic detection module, and obtain the acoustic time T of the zero-stress longitudinal wave during the tensile test of the workpiece under test. L0 and the acoustic time T of zero-stress transverse waves S0 And calculate the longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S ;

[0010] It is also used to divide the cross-section of the workpiece under test into several grids of preset sizes, calculate the propagation distance L of the ultrasonic longitudinal and transverse waves, and determine the propagation time T of the zero-stress longitudinal wave. L0 Acoustic time T of zero-stress transverse waves S0 Given the propagation distance L, calculate the propagation velocities V of the ultrasonic longitudinal and transverse waves when there is zero stress in the detection area. L0 and V S0 The actual propagation time T of the longitudinal and transverse ultrasonic waves to each grid of the workpiece under test is measured. L and T S ;

[0011] It is also used to determine the actual propagation time T of the longitudinal and transverse waves in each grid of the detection area. L and T S Based on the travel time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves in all grid regions of the cross-section of the workpiece under test are calculated, and the longitudinal and transverse wave velocity tomographic images of the cross-section of the workpiece under test are generated.

[0012] It is also used to determine the propagation velocities V of longitudinal and transverse waves at zero stress based on the longitudinal and transverse wave velocity tomography images of the cross-section of the workpiece under test. L0 and V S0 and longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε SThe residual stress at each location on the cross-section of the workpiece under test is calculated and integrated to generate a residual stress tomographic image at each location on the cross-section of the workpiece under test.

[0013] In this technical solution, when it is necessary to detect the residual stress of the workpiece under test, the control module controls the ultrasonic detection module to emit and receive longitudinal and transverse waves towards the workpiece under test. The control module then determines the corresponding acoustic time T of the longitudinal and transverse waves when the workpiece is under zero stress. L0 and T S0 Calculate the longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S Based on the propagation distance L of longitudinal and transverse waves and the corresponding acoustic time T L0 and T S0 Calculate the propagation velocities V of the ultrasonic longitudinal and transverse waves when the detection area is under zero stress. L0 and V S0 The actual propagation time T of the longitudinal and transverse ultrasonic waves to each grid of the workpiece under test is measured. L and T S Finally, the output is a residual stress tomography image of each position on the cross section of the workpiece under test within the detection range covered by the ultrasonic detection module.

[0014] Secondly, a workpiece stress distribution inversion method, employing a workpiece stress distribution inversion system based on longitudinal and transverse wave fusion proposed in any of the technical solutions in the first aspect, includes:

[0015] The acoustic time T of the zero-stress longitudinal wave is obtained from the workpiece under test through a tensile test. L0 and the acoustic time T of zero-stress transverse waves S0 The longitudinal wave acoustic elastic coefficient ε is calculated using the control module. L and transverse wave acoustic elastic coefficient ε S ;

[0016] The ultrasonic detection module emits ultrasonic waves of a specified frequency to the workpiece under test, dividing the cross-section of the workpiece into several grids of preset size. The control module calculates the propagation distance L of the longitudinal and transverse waves of the ultrasonic waves.

[0017] Using the control module, based on the acoustic time T of the zero-stress longitudinal wave L0 Acoustic time T of zero-stress transverse waves S0 Given the propagation distance L, calculate the propagation velocities V of the ultrasonic longitudinal and transverse waves when there is zero stress in the detection area. L0 and V S0 The actual propagation time T of the longitudinal and transverse ultrasonic waves to each grid of the workpiece under test is measured. L and T S ;

[0018] Using the control module, the actual propagation time T of the longitudinal and transverse waves in each grid of the detection area is determined. Land T S Based on the travel time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves in all grid regions of the cross section of the workpiece under test are calculated, and longitudinal and transverse wave velocity tomographic images of the cross section of the workpiece under test are generated.

[0019] Using the control module, based on the longitudinal and transverse wave velocity tomography images of the cross-section of the workpiece under test, the propagation velocities V of the longitudinal and transverse waves at zero stress are determined. L0 and V S0 and longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S The residual stress at each location on the cross-section of the workpiece under test is calculated and integrated to generate a residual stress tomographic image at each location on the cross-section of the workpiece under test.

[0020] In this technical solution, the acoustoelastic coefficient of the workpiece under zero stress is obtained through a tensile test. After emitting ultrasonic waves of a specified frequency onto the workpiece, the propagation distance from the ultrasonic detection module to each grid in the corresponding ultrasonic detection area on the workpiece is calculated. This yields the actual propagation time of the longitudinal and transverse waves in each grid of the ultrasonic detection area. Based on the travel time residual inversion algorithm, the actual propagation velocities of the longitudinal and transverse waves at all depths (i.e., all grids) of the cross-section where the ultrasonic detection area is located are inverted. These are then summarized to generate a velocity tomographic image of the longitudinal and transverse waves across the cross-section of the workpiece. Finally, based on the propagation velocities of the longitudinal and transverse waves at zero stress on the workpiece, the velocity tomographic image containing the actual propagation velocities of the longitudinal and transverse waves, and the longitudinal wave acoustoelastic coefficient ε, the solution is determined. L and transverse wave acoustic elastic coefficient ε S This method calculates the residual stress at different depths of the cross-section of the workpiece under test and generates a residual stress tomographic image. This method has small measurement errors, and the residual stress tomographic image helps analyze the distribution of residual stress in the workpiece. It obtains the residual stress distribution of the cross-section of the workpiece without moving it by means of rotation, which is of great significance for calculating the lifespan of the workpiece, its usage, and improving processing technology.

[0021] Thirdly, a computer-readable storage medium having a computer program stored thereon, wherein a processor executes the computer program to perform the following steps:

[0022] Acoustic time T of zero-stress longitudinal wave of workpiece under test L0 and the acoustic time T of zero-stress transverse waves S0 The longitudinal wave acoustic elastic coefficient ε is generated. L and transverse wave acoustic elastic coefficient ε S ;

[0023] Acquire ultrasonic signal data about the workpiece under test, divide the cross-section of the workpiece under test into several grids of preset size, and calculate the propagation distance L of the ultrasonic longitudinal wave and transverse wave.

[0024] According to the acoustic time T of zero-stress longitudinal waves L0 Acoustic time T of zero-stress transverse waves S0 Given the propagation distance L, calculate the propagation velocities V of the ultrasonic longitudinal and transverse waves when there is zero stress in the detection area. L0 and V S0 The actual propagation time T of the ultrasonic longitudinal wave and its arrival at each grid of the workpiece was measured. L and T S ;

[0025] Based on the actual propagation time T of the ultrasonic longitudinal and transverse waves in each grid of the detection area L and T S Based on the travel time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves in all grid regions of the cross-section of the workpiece under test are calculated, and the longitudinal and transverse wave velocity tomographic images of the cross-section of the workpiece under test are generated.

[0026] Based on the longitudinal and transverse wave velocity tomography images of the cross-section of the workpiece under test, the propagation velocities V of the longitudinal and transverse waves at zero stress are... L0 and V S0 and longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S The residual stress at each location on the cross-section of the workpiece under test is calculated, and a tomographic image of the residual stress at each location on the cross-section of the workpiece under test is generated.

[0027] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0028] (1) The system, through the cooperation of an ultrasonic detection module including a longitudinal wave probe group and a transverse wave probe group, and a control module, can realize multi-mode fusion detection of a cross section of the workpiece under test using both longitudinal and transverse wave ultrasonic modes, and measure all depths of the coverage area without the need for a moving device; and the data obtained by multiple detections at a single detection point can reduce the measurement error of residual stress and improve the measurement accuracy.

[0029] (2) The method obtains the acoustoelastic coefficient of the workpiece under longitudinal and transverse waves through tensile testing, which can greatly reduce the error of ultrasonic residual stress detection. Based on the travel time residual inversion algorithm, combined with the fusion calculation of longitudinal and transverse waves, the residual stress distribution image of the workpiece under test within the array coverage area is generated, which has important theoretical and practical significance for workpiece quality inspection, fatigue life assessment, production quality inspection, etc. Attached Figure Description

[0030] Figure 1This is a schematic diagram of the workpiece stress distribution inversion system.

[0031] Figure 2 This is a schematic diagram of the ultrasonic detection module.

[0032] Figure 3 This is a schematic diagram illustrating the working principle of the ultrasonic detection module.

[0033] Figure 4 This is a schematic diagram of the adjustable connection module structure in Example 1;

[0034] Figure 5 This is a schematic diagram of the height adjustment module structure in Example 1;

[0035] Figure 6 Flowchart of the workpiece stress distribution inversion method;

[0036] Figure 7 This is an example image of the shear wave velocity tomography in Example 2;

[0037] Figure 8 This is an example image of the longitudinal wave velocity tomography in Example 2;

[0038] Figure 9 This is an example image of residual stress tomography in Example 2. Detailed Implementation

[0039] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0040] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions.

[0041] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0042] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] Example 1

[0044] This embodiment provides a workpiece stress distribution inversion system based on longitudinal and transverse wave fusion. (See attached document.) Figures 1-3 The system includes an ultrasonic detection module 1 and a workbench 2. The ultrasonic detection module 1 is connected to the workbench 2 and is communicatively connected to the control module. The ultrasonic detection module 1 includes a longitudinal wave probe group and a transverse wave probe group, which are used to transmit and receive longitudinal waves and transverse waves, respectively.

[0045] The control module is used to control the ultrasonic detection module 1 to transmit and receive longitudinal and transverse waves, receive longitudinal and transverse wave signal data returned by the ultrasonic detection module 1, and obtain the acoustic time T of the zero-stress longitudinal wave during the tensile test of the workpiece under test.L0 and the acoustic time T of zero-stress transverse waves S0 And calculate the longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S ;

[0046] It is also used to divide the cross-section of the workpiece under test into several grids of preset sizes, calculate the propagation distance L of the ultrasonic longitudinal and transverse waves, and determine the propagation time T of the zero-stress longitudinal wave. L0 Acoustic time T of zero-stress transverse waves S0 Given the propagation distance L, calculate the propagation velocities V of the ultrasonic longitudinal and transverse waves when there is zero stress in the detection area. L0 and V S0 The actual propagation time T of the ultrasonic longitudinal and transverse waves to each grid of the workpiece under test was measured. L and T S ;

[0047] It is also used to determine the actual propagation time T of the longitudinal and transverse waves in each grid of the detection area. L and T S Based on the travel time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves at all positions in the cross section of the workpiece 3 under test are calculated, and the longitudinal and transverse wave velocity tomographic images of the cross section of the workpiece 3 under test are generated.

[0048] It is also used to determine the propagation velocities V of longitudinal and transverse waves at zero stress based on the longitudinal and transverse wave velocity tomography images of the cross-section of the workpiece under test. L0 and V S0 and longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S The residual stress at each position of the cross section of the workpiece 3 under test is calculated by fusion, and residual stress tomography images at each position of the cross section of the workpiece 3 under test are generated.

[0049] As a non-limiting example, the ultrasonic detection module 1 can emit and receive ultrasonic waves of several specified frequencies.

[0050] In a specific implementation process, the workpiece sample to be tested is first obtained and placed at the ultrasonic emission direction of the ultrasonic detection module 1. A tensile test is then conducted on the workpiece sample within the material's elastic range according to GB / T228.1 at room temperature (10℃~35℃). The operator starts and stops the ultrasonic detection module 1 from emitting longitudinal and transverse waves via the control module, and calculates the longitudinal wave acoustic elastic coefficient ε of the workpiece 3 using the control module. L and transverse wave acoustic elastic coefficient ε SAfter obtaining the relevant acoustic elastic coefficients of the workpiece under test, the workpiece 3 is placed close to the ultrasonic emission direction of the ultrasonic detection module 1. The ultrasonic detection module 1 is controlled by the control module to continuously emit and receive ultrasonic waves of a specified frequency. During this process, the transmission time and propagation path of the longitudinal and transverse waves are recorded by the control module, and the propagation distance L of the ultrasonic longitudinal and transverse waves from the emission point to each grid of the ultrasonic detection area on the workpiece under test, and the propagation speed V of the ultrasonic longitudinal and transverse waves in the detection area at zero stress are obtained. L0 and V S0 The actual propagation time T of the ultrasonic longitudinal and transverse waves in the detection area L and T S Based on this, the staff controls the control module to calculate the actual propagation velocities of longitudinal and transverse waves at all depth positions in the cross-section of the current ultrasonic detection area of ​​the workpiece under test, and generates longitudinal and transverse wave velocity tomographic images of the cross-section of the workpiece under test. Then the staff can stop the emission of ultrasonic longitudinal and transverse waves and instruct the control module to output residual stress tomographic images of each position in the cross-section of the detection area of ​​the workpiece under test covered by ultrasonic detection module 1.

[0051] In an optional embodiment, the operator can continue to move the workpiece 3 under test, detect multiple cross-sections of the workpiece 3 under test, and fuse and output residual stress tomographic images of each depth position of the multiple cross-sections.

[0052] In a preferred embodiment, see Figure 1 , Figure 4 The ultrasonic detection module 1 is connected to the workbench 2 via an adjustable connection module. The adjustable connection module includes a two-degree-of-freedom adjustment component 4, a first connecting component 5, a second connecting component 6, and a rotating component 7. One side of the rotating component 7 is fixedly connected to the workbench 2, and the other side is rotatably connected to one end of the first connecting component 5. The end of the first connecting component 5 away from the rotating component 4 is rotatably connected to one end of the second connecting component 6. The other end of the second connecting component 6 is rotatably connected to the two-degree-of-freedom adjustment component 4. The end of the two-degree-of-freedom adjustment component 4 away from the second connecting component 6 is connected to the ultrasonic detection module 1, which is used to drive the ultrasonic detection module 1 to rotate up and down and swing left and right.

[0053] In this preferred embodiment, when using ultrasonic waves to detect the workpiece, the ultrasonic detection module can be flipped around the center of the rotating component as the axis of rotation. The first connecting member rotates around its connection with the rotating component, and the second connecting member rotates around its connection with the first connecting member, causing the first and second connecting members to fold or extend. Through the cooperation of the first and second connecting members, the vertical height and horizontal length of the ultrasonic detection module can be adjusted. Combined with the rotation of the rotating component around its center, the ultrasonic detection module can be adjusted vertically and horizontally. The two-degree-of-freedom adjustment member rotates around its connection with the second connecting member, allowing the ultrasonic detection module to rotate up and down and swing left and right in its original position. Through the structural cooperation design between the two-degree-of-freedom adjustment member, the first connecting member, the second connecting member, and the rotating component, the ultrasonic detection module can rotate up and down, swing left and right, and extend and retract at any distance, achieving the purpose of detecting any position and angle of the workpiece.

[0054] It is understood that the two-degree-of-freedom adjustment component 4 can rotate about its own transverse axis and swing about its own longitudinal axis, with the transverse axis and longitudinal axis perpendicular to each other, thereby realizing the two-degree-of-freedom adjustment of the ultrasonic detection module 1. Exemplarily, the two-degree-of-freedom adjustment component 4 is a two-axis rotating component.

[0055] In this preferred embodiment, the adjustable connection module allows the ultrasonic detection module 1 to adjust the ultrasonic incident direction and ultrasonic propagation distance of the workpiece 3 under test.

[0056] As a non-limiting example, the first connector 5 is a rigid connector and / or a flexible connector, and the second connector 6 is a rigid connector and / or a flexible connector.

[0057] In one specific implementation, the first connector 5 is a rigid connecting rod, and the second connector 6 is a flexible metal hose.

[0058] In another specific implementation, both the first connector 5 and the second connector 6 are rigid connecting rods.

[0059] When the operator deems the ultrasonic detection module too far from the cross-section of the workpiece to be tested, the first connecting member 5 and the second connecting member 6 can be rotated to extend them, thereby shortening the relative distance between the ultrasonic detection module 1 and the cross-section of the workpiece 3. Similarly, the first connecting member 5 and the second connecting member 6 can also be rotated to fold them, thus shortening the relative distance between the ultrasonic detection module 1 and the cross-section of the workpiece 3.

[0060] As a non-limiting example, the rotating component 7 is a rotatable connecting block, allowing the first connecting member 5 to rotate about the axis at which it connects with the rotating component 7; meanwhile, the rotating component 7 includes fasteners or clips, which can lock the rotation angle of the rotating component 7.

[0061] In a specific implementation, the ultrasonic detection module 1 can achieve three degrees of freedom of movement and rotation through the two-degree-of-freedom adjustment component 4 and the rotation component 7.

[0062] In an optional embodiment, the adjustable connection module further includes a rotating component disposed between the ultrasonic detection module 1 and the two-degree-of-freedom adjustment member 4. One side of the rotating component is rotatably connected to the end of the two-degree-of-freedom adjustment member 4, and the other side is connected to the ultrasonic detection module 1. That is, the two-degree-of-freedom adjustment member 4 is connected to the ultrasonic detection module 1 via the rotating component. This rotating component increases the degree of freedom, allowing the ultrasonic detection module 1 to rotate around its center in situ, providing operators with more options for the ultrasonic incident angle, which is particularly suitable for scenarios where the ultrasonic detection module is strip-shaped.

[0063] As a non-limiting example, the rotating component includes, but is not limited to, a gyro ball or a turntable.

[0064] In one specific implementation, the ultrasonic detection module 1, through the two-degree-of-freedom adjustment component 4 and the rotating component, can adjust the angle range to ±45° on the horizontal plane and the angle range to 0-50° on the vertical plane.

[0065] In another specific implementation, the ultrasonic detection module 1 can rotate around a fixed point within an angle range of ±120°.

[0066] In a preferred embodiment, see Figure 2 The longitudinal wave probe group includes at least one first longitudinal wave probe and at least one second longitudinal wave probe, and the transverse wave probe group includes at least one first transverse wave probe and at least one second transverse wave probe; wherein, the input terminals of the first longitudinal wave probe and the first transverse wave probe are respectively connected to the output terminal of the control module for transmitting longitudinal waves and transverse waves; the output terminals of the second longitudinal wave probe and the second transverse wave probe are respectively connected to the input terminal of the control module for receiving longitudinal wave and transverse wave signal data.

[0067] In this preferred embodiment, when it is necessary to inspect a workpiece, the control module controls the first longitudinal wave probe and the first transverse wave probe via the output terminal to emit longitudinal waves and transverse waves respectively, and receives the corresponding longitudinal wave and transverse wave data collected by the second longitudinal wave probe and the second transverse wave probe via the input terminal respectively.

[0068] Exemplary, the first longitudinal wave probe and the first transverse wave probe are located in the same vertical or horizontal direction, and the second longitudinal wave probe and the second transverse wave probe are located in the same vertical or horizontal direction.

[0069] In a specific implementation, the longitudinal wave probe group includes a first longitudinal wave probe and a second longitudinal wave probe, and the transverse wave probe group includes a first transverse wave probe and a second transverse wave probe. The control module controls the first longitudinal wave probe and the first transverse wave probe to perform ultrasonic longitudinal wave and transverse wave transmission tasks respectively through the output terminal. The control module acquires the corresponding data of ultrasonic longitudinal wave and transverse wave received by the second longitudinal wave probe and the second transverse wave probe through the input terminal.

[0070] In another specific implementation, the longitudinal wave probe group includes one first longitudinal wave probe and three second longitudinal wave probes, and the transverse wave probe group includes one first transverse wave probe and three second transverse wave probes. The control module controls the first longitudinal wave probe and the first transverse wave probe to perform ultrasonic longitudinal wave and transverse wave transmission tasks respectively through the output terminal. The control module acquires the corresponding data of ultrasonic longitudinal wave and transverse wave received by the second longitudinal wave probe and the second transverse wave probe through the input terminal. At this time, the ultrasonic detection module can realize one transmission and multiple reception.

[0071] As an example, each first longitudinal wave probe / first transverse wave probe emits one ultrasonic longitudinal wave / transverse wave, which is received by the other probes. Therefore, several ultrasonic longitudinal waves / transverse waves can be emitted throughout the entire operation.

[0072] In a preferred embodiment, the workpiece stress distribution inversion system further includes a conveyor belt 8 for conveying the workpiece 3 to be tested, the conveyor belt 8 being connected to an external drive mechanism; the conveyor belt 8 is located below the ultrasonic detection module 1 and is connected to the worktable 2.

[0073] Since the ultrasonic detection module can only detect within its coverage area each time it emits and receives longitudinal and transverse waves, for larger workpieces, it is necessary to manually move the workpiece 3 multiple times to achieve full coverage of the detection area. However, in this preferred embodiment, the conveyor belt 8 enables automatic transfer of the workpiece 3. After the operator places the workpiece 3 on the conveyor belt, the detection is performed. When the workpiece needs to be moved, the control module or the operator controls the external drive mechanism to work, thereby driving the conveyor belt 8. The friction between the contact surface between the conveyor belt 8 and the workpiece 3 causes the workpiece 3 to move.

[0074] As a non-limiting example, the conveyor belt 8 includes a plurality of side-by-side conveyor rollers, and the external drive mechanism is a motor.

[0075] In one specific implementation process, the workpiece 3 to be tested is placed on the conveyor belt 8, and the external drive mechanism is controlled by the control module. The operator controls the working state of the external drive mechanism through the control module, thereby controlling the conveyor belt 8 to transport the workpiece 3 to be tested.

[0076] In another specific implementation, the workpiece to be tested is placed on conveyor belt 8, and the external drive mechanism is electrically connected to a switch. The operator controls the operating state of the external drive mechanism by opening and closing the switch, thereby controlling the conveying distance of the workpiece to be tested on conveyor belt 8.

[0077] In an optional embodiment, the workpiece stress distribution inversion system further includes a height adjustment module 9 for adjusting the height of the conveyor belt 8, the conveyor belt 8 being connected to the worktable 2 via the height adjustment module 9.

[0078] In this optional embodiment, the height adjustment module 9 allows the workpiece 3 to be tested, placed on the conveyor belt 8, to move vertically along with the conveyor belt 8. This enables the ultrasonic detection module 1 to be in close contact with the surface of the workpiece 3 and allows the workpiece stress distribution inversion system to adapt to more workpieces of different diameters.

[0079] In one specific implementation, the conveyor belt 8 is positioned above the height adjustment module 9 and is connected to the workbench 2 through several height adjustment modules 9.

[0080] In another specific implementation, the conveyor belt 8 is positioned below several height adjustment modules.

[0081] As a non-limiting example, the workbench 2 includes a plane and a plurality of support legs, see reference. Figure 5 The height adjustment module 9 is a support component with a through hole in its center. The diameter of the through hole is adapted to the support leg of the workbench. Bolt clamping holes are provided outside the through hole, allowing M10 bolts and nuts to clamp the support leg, thus fixing the relative position of the height adjustment module 9 and the support leg. By adjusting the bolts, the height adjustment module 9 moves along the support leg, causing the conveyor belt 8 to move longitudinally along the support leg. This allows the workpiece stress distribution inversion system to adapt to workpieces of various thicknesses, ensuring that the surface of the workpiece 6 to be tested, placed on the conveyor belt 8, is in close contact with the ultrasonic detection module.

[0082] As a non-limiting example, the workbench 2 is a plane, and the height adjustment module 9 is a clamping component, including a clamping part, a telescopic part, and a connecting part. The clamping part is fastened to the edge of the workbench 2 surface by bolts. One end of the clamping part is fixedly connected to the telescopic part, and the other end of the telescopic part is fixedly connected to the connecting part. The connecting part is connected to the conveyor belt 8. When the operator needs to adjust the height of the conveyor belt 8, the telescopic part of the height adjustment module 9 is adjusted to adaptively change the relative distance between the connecting part and the conveyor belt 8 and the ultrasonic detection module 1.

[0083] Example 2

[0084] This embodiment provides a method for inverting workpiece stress distribution; see reference... Figure 1 , Figure 3 , Figure 6 The workpiece stress distribution inversion system based on longitudinal and transverse wave fusion proposed in Example 1 includes:

[0085] The acoustic time T of the zero-stress longitudinal wave is obtained from the workpiece under test through a tensile test. L0 and the acoustic time T of zero-stress transverse waves S0 The longitudinal wave acoustic elastic coefficient ε is calculated using the control module. L and transverse wave acoustic elastic coefficient ε S ;

[0086] The ultrasonic detection module 1 emits ultrasonic waves of a specified frequency to the workpiece to be tested, dividing the cross-section of the workpiece into several grids of preset size. The control module calculates the propagation distance L of the longitudinal and transverse waves of the ultrasonic waves.

[0087] Using the control module, based on the acoustic time T of the zero-stress longitudinal wave L0 Acoustic time T of zero-stress transverse waves S0 Given the propagation distance L, calculate the propagation velocities V of the ultrasonic longitudinal and transverse waves when there is zero stress in the detection area. L0 and V S0 The actual propagation time T of the ultrasonic wave reaching each grid of the workpiece was measured.

[0088] Using the control module, the actual propagation time T of the longitudinal and transverse waves in each grid of the detection area is determined. L and T S Based on the travel-time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves in all grid regions of the cross-section of the workpiece under test are calculated, and the resulting tomographic images of longitudinal and transverse wave velocities of the cross-section of the workpiece under test are generated. (See reference...) Figure 7 , Figure 8 ;

[0089] Using the control module, based on the longitudinal and transverse wave velocity tomography images of the cross-section of the workpiece under test, the propagation velocities V of the longitudinal and transverse waves at zero stress are determined. L0and V S0 and longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S The residual stress at various locations on the cross-section of the workpiece under test is calculated and integrated to generate residual stress tomographic images at each location on the cross-section of the workpiece under test. (See reference...) Figure 9 .

[0090] It is understandable that in a single detection, if the ultrasonic detection position and ultrasonic state of the workpiece under test do not change, the area detected by ultrasonic detection module 1 is fixed, and it is impossible to completely scan the entire cross-section of the workpiece under test. Therefore, the actual propagation time obtained is the propagation time of the ultrasonic wave in each grid region. By introducing the travel time residual inversion algorithm, the actual propagation speed at all positions in the cross-section of the entire detection area of ​​the workpiece under test can be obtained from the actual propagation time of the ultrasonic wave in each grid region.

[0091] It can be understood that the propagation speeds V of the longitudinal and transverse waves of the ultrasonic wave at zero stress are... L0 and V S0 It is the acoustic time T when the propagation distance L is divided by the zero stress of the longitudinal and transverse waves, respectively. L0 and T S0 get.

[0092] For example, see Figure 3 The propagation distance L is formulated as follows:

[0093]

[0094] Where L represents the propagation distance of longitudinal and transverse waves, l represents the size of a single grid, X1 represents the number of grids between the grid to be detected and the probe used to emit ultrasonic waves in the X direction, X2 represents the number of grids between the grid to be detected and the probe used to receive ultrasonic waves in the X direction, Z1 represents the number of grids between the grid to be detected and the probe used to emit ultrasonic waves in the Z direction, and Z2 represents the number of grids between the grid to be detected and the probe used to receive ultrasonic waves in the Z direction.

[0095] It is understandable that the propagation distance will be different for different grids and different probe groups, and L is essentially a matrix.

[0096] In a specific implementation, the formula for the travel time residual inversion algorithm is as follows:

[0097]

[0098] Where T represents absolute travel time, i.e., actual propagation time T L or T S It is obtained through observation; s(x) represents the slowness measure, and L represents the propagation distance of the ultrasound.

[0099] The expression for the slow metric s(x) is as follows:

[0100] s(x)=L / T

[0101] Where T represents absolute travel time; L represents the propagation distance of longitudinal and transverse waves.

[0102] The actual propagation speeds V of the longitudinal and transverse waves L and V S The expression is as follows:

[0103]

[0104] Where V represents the actual propagation speed of the longitudinal or transverse wave. L or V S .

[0105] In a specific implementation process, according to GB / T228.1, a tensile test is conducted on the workpiece sample under normal temperature (10℃~35℃) to calibrate the longitudinal and transverse wave acoustoelastic coefficients of the workpiece. Subsequently, ultrasonic waves of a specified frequency are emitted to the workpiece and the returned ultrasonic data is received. The propagation distance from the ultrasonic detection module to each grid of the corresponding ultrasonic detection area on the workpiece is calculated, and thus the actual propagation time T of the longitudinal and transverse waves of the ultrasonic waves to each grid of the workpiece is obtained. L and T S Based on the travel-time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves at all depths of the cross-section where the ultrasonic detection area is located are inverted, and these velocities are summarized to generate longitudinal and transverse wave velocity tomographic images of the cross-section of the workpiece under test. Finally, based on the propagation velocities of longitudinal and transverse waves at zero stress on the workpiece under test, and the velocity tomographic images containing the actual propagation velocities of longitudinal and transverse waves, the residual stress at different depths of the cross-section of the workpiece under test is calculated and a residual stress tomographic image is generated. This process is repeated, continuously moving the workpiece under test, until a three-dimensional residual stress distribution image of the workpiece under test is finally formed in the control module.

[0106] By obtaining the acoustoelastic coefficients of the workpiece under longitudinal and transverse waves through tensile testing, the error of ultrasonic residual stress detection can be greatly reduced. Based on the travel time residual inversion algorithm, combined with the fusion calculation of longitudinal and transverse waves, the residual stress distribution image of the cross section of the workpiece under test within the array coverage area can be generated without continuously moving the ultrasonic detection module to complete multiple detections of the same cross section. The residual stress at all locations within the cross section of the detection area can be obtained.

[0107] In a preferred embodiment, the calculation of the longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S In the middle, the longitudinal wave acoustic elastic coefficient εL The expression is:

[0108]

[0109] In the formula, K L Indicates the longitudinal wave stress coefficient;

[0110] transverse wave acoustic elastic coefficient ε S The expression is:

[0111]

[0112] In the formula, K S This represents the transverse wave stress coefficient.

[0113] In a preferred embodiment, the residual stress at each location on the cross-section of the workpiece under test is calculated using the following formula:

[0114]

[0115] Where σ represents the measured stress value.

[0116] Example 3

[0117] This embodiment proposes a computer-readable storage medium storing a computer program thereon. When a processor executes the computer program, it implements the technical solution proposed in Embodiment 2, including:

[0118] Acoustic time T of zero-stress longitudinal wave of workpiece under test L0 and the acoustic time T of zero-stress transverse waves S0 Calculate the longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S ;

[0119] Acquire ultrasonic signal data about the workpiece under test, divide the cross-section of the workpiece under test into several grids of preset size, and calculate the propagation distance L of the ultrasonic waves;

[0120] According to the acoustic time T of zero-stress longitudinal waves L0 Acoustic time T of zero-stress transverse waves S0 Given the propagation distance L, calculate the propagation velocities V of the ultrasonic longitudinal and transverse waves when there is zero stress in the detection area. L0 and V S0 The actual propagation time T of the ultrasonic longitudinal wave and its arrival at each grid of the workpiece was measured. L and T S ;

[0121] Based on the actual propagation time T of the longitudinal and transverse waves in each grid of the detection area L and T SBased on the travel time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves in all grid regions of the cross-section of the workpiece under test are calculated, and the longitudinal and transverse wave velocity tomographic images of the cross-section of the workpiece under test are generated.

[0122] Based on the longitudinal and transverse wave velocity tomography images of the cross-section of the workpiece under test, the propagation velocities V of the longitudinal and transverse waves at zero stress are... L0 and V S0 and longitudinal wave acoustic elastic coefficient ε L and transverse wave acoustic elastic coefficient ε S The residual stress at each location on the cross-section of the workpiece under test is calculated, and a tomographic image of the residual stress at each location on the cross-section of the workpiece under test is generated.

[0123] The same or similar labels correspond to the same or similar parts;

[0124] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0125] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A workpiece stress distribution inversion system based on longitudinal and transverse wave fusion, comprising an ultrasonic detection module (1) and a worktable (2), characterized in that, The ultrasonic detection module (1) is connected to the workbench (2) and communicates with the control module; The ultrasonic detection module (1) includes a longitudinal wave probe group and a transverse wave probe group, which are used to transmit and receive ultrasonic longitudinal waves and transverse waves respectively, and transmit the received longitudinal wave and transverse wave signal data back to the control module. The control module is used to control the ultrasonic detection module (1) to transmit and receive longitudinal and transverse waves, receive longitudinal and transverse wave signal data returned by the ultrasonic detection module (1), and obtain the acoustic time of the zero-stress longitudinal wave during the tensile test of the workpiece under test. and the acoustic time of zero-stress transverse waves And calculate the longitudinal wave acoustic elastic coefficient. and transverse wave acoustic elastic coefficient ; It is also used to divide the cross-section of the workpiece under test into several grids of preset sizes, and to calculate the propagation distance of ultrasonic longitudinal and transverse waves. According to the acoustic time of zero-stress longitudinal waves Acoustic time of zero-stress transverse waves and transmission distance Calculate the propagation speeds of ultrasonic longitudinal and transverse waves when the detection area is under zero stress. and Measure the actual propagation time of ultrasonic longitudinal and transverse waves to each grid of the workpiece under test. ; It is also used to determine the actual propagation time of longitudinal and transverse waves in each grid of the detection area. and Based on the travel time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves in all grid regions of the cross section of the workpiece (3) under test are calculated, and the longitudinal and transverse wave velocity tomography images of the cross section of the workpiece (3) under test are generated. It is also used to determine the propagation velocities of longitudinal and transverse waves at zero stress based on tomographic images of longitudinal and transverse wave velocities of the cross-section of the workpiece under test. and and longitudinal wave acoustic elastic coefficient and transverse wave acoustic elastic coefficient The residual stress at each position of the cross section of the workpiece (3) under test is calculated by fusion, and a residual stress tomography image at each position of the cross section of the workpiece (3) under test is generated. The ultrasonic detection module (1) is connected to the workbench (2) via an adjustable connection module. The adjustable connection module includes a two-degree-of-freedom adjustment component (4), a first connector (5), a second connector (6), and a rotating component (7). One side of the rotating component (7) is fixedly connected to the workbench (2), and the other side is rotatably connected to one end of the first connector (5). The end of the first connector (5) away from the rotating component (7) is rotatably connected to one end of the second connector (6). The other end of the second connector (6) is rotatably connected to the two-degree-of-freedom adjustment component (4). The end of the two-degree-of-freedom adjustment component (4) away from the second connector (6) is connected to the ultrasonic detection module (1) to drive the ultrasonic detection module (1) to rotate up and down and swing left and right.

2. The workpiece stress distribution inversion system based on longitudinal and transverse wave fusion according to claim 1, characterized in that, The adjustable connection module also includes a rotating component, which is located between the ultrasonic detection module (1) and the two-degree-of-freedom adjustment component (4); one side of the rotating component is rotatably connected to the end of the two-degree-of-freedom adjustment component (4), and the other side is connected to the ultrasonic detection module (1).

3. The workpiece stress distribution inversion system based on longitudinal and transverse wave fusion according to claim 1, characterized in that, The longitudinal wave probe group includes at least one first longitudinal wave probe and at least one second longitudinal wave probe, and the transverse wave probe group includes at least one first transverse wave probe and at least one second transverse wave probe; wherein, the input terminals of the first longitudinal wave probe and the first transverse wave probe are respectively connected to the output terminal of the control module for transmitting longitudinal waves and transverse waves; the output terminals of the second longitudinal wave probe and the second transverse wave probe are respectively connected to the input terminal of the control module for receiving longitudinal wave and transverse wave signal data.

4. A workpiece stress distribution inversion system based on longitudinal and transverse wave fusion according to any one of claims 1-3, characterized in that, It also includes a conveyor belt (8) for conveying the workpiece to be tested, the conveyor belt (8) being connected to an external drive mechanism; the conveyor belt (8) is located below the ultrasonic detection module (1) and is connected to the worktable (2).

5. The workpiece stress distribution inversion system based on longitudinal and transverse wave fusion according to claim 4, characterized in that, It also includes a height adjustment module (9) for adjusting the height of the conveyor belt (8), which is connected to the workbench (2) via the height adjustment module (9).

6. A method for inverting workpiece stress distribution based on the workpiece stress distribution inversion system according to any one of claims 1-5, characterized in that, include: Acoustic time of zero-stress longitudinal waves obtained from the workpiece under test through tensile testing and the acoustic time of zero-stress transverse waves The longitudinal wave acoustic elastic coefficient is calculated using the control module. and transverse wave acoustic elastic coefficient ; The ultrasonic detection module (1) emits ultrasonic waves of a specified frequency to the workpiece under test, dividing the cross-section of the workpiece into several grids of preset size. The control module calculates the propagation distance of the longitudinal and transverse waves of the ultrasonic waves. ; Using the control module, based on the acoustic time of the zero-stress longitudinal wave Acoustic time of zero-stress transverse waves and transmission distance Calculate the propagation speeds of ultrasonic longitudinal and transverse waves when the detection area is under zero stress. and Measure the actual propagation time of ultrasonic longitudinal and transverse waves to each grid of the workpiece under test. ; Using the control module, the actual propagation time of the P-wave and S-wave in each grid of the detection area is determined. Based on the travel time residual inversion algorithm, the actual propagation velocities of longitudinal and transverse waves in all grid regions of the cross section of the workpiece under test are calculated and summarized to generate longitudinal and transverse wave velocity tomographic images of the cross section of the workpiece under test. Using the control module, the propagation velocities of longitudinal and transverse waves at zero stress are determined based on the tomographic images of the longitudinal and transverse wave velocities of the cross-section of the workpiece under test. and and longitudinal wave acoustic elastic coefficient and transverse wave acoustic elastic coefficient The residual stress at each location on the cross-section of the workpiece under test is calculated and integrated to generate a residual stress tomographic image at each location on the cross-section of the workpiece under test.

7. The workpiece stress distribution inversion method according to claim 6, characterized in that, The calculation of the longitudinal wave acoustic elastic coefficient and transverse wave acoustic elastic coefficient In the middle, the longitudinal wave acoustic elastic coefficient The expression is: In the formula, Indicates the longitudinal wave stress coefficient; transverse wave acoustic elastic coefficient The expression is: In the formula, This represents the transverse wave stress coefficient.

8. A method for inverting workpiece stress distribution according to any one of claims 6-7, characterized in that, The residual stress at various locations on the cross-section of the workpiece under test is calculated using the following formula: in, Indicates the measured stress value; This represents the propagation speed of a longitudinal wave under stress. This indicates the propagation speed of a transverse wave under stress.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the workpiece stress distribution inversion method of the workpiece stress distribution inversion system as described in any one of claims 6 to 8.

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